Tiny Sea Otter Siblings Fight the Odds

Twin sea otters are exceptionally rare, accounting for about 2 percent of births. But the demands of raising two pups are too great for sea otter mothers, and one pup is usually abandoned after a few days. Photo: Mike Baird/Flickr

The twins would alternate between nursing and being groomed, sometimes floating near mom. Photo: Mike Baird/Flickr

"There were times when they were just laying there sleeping," Staedler said. Photo: Mike Baird/Flickr

"If one drifted away, she would go back and pick it up and get it and put it on top of her," Staedler said, describing the otters' mom. Photo: Mike Baird/FlickrPhoto: Mike Baird/Flickr

"It would be a lot of work to feed two of these little guys," Staedler said. "Metabolically, it's not possible. They don't have the physiology to be able to do that." Photo: Mike Baird/Flickr

Pups ride around on top of mom to stay warm, said Michelle Staedler. Photo: Mike Baird/Flickr

Sea otter pups do a lot of sleeping when they're so young. Photo: Mike Baird/Flickr

Sea otters have two nipples down by their tail. Sometimes, pups fall asleep while nursing -- just like little kids. Photo: Mike Baird/Flickr

For several days this week, these two tiny sea otter siblings were floating around on their mom’s belly in Morro Bay, in central California. Alternately nursing and being groomed, or occasionally floating beside her, the little furballs are a rare pair: Roughly 2 percent of sea otter pregnancies result in the birth of more than one pup.

Normally, sea otters only give birth to one pup at a time. The first twin otters (.pdf) were only reported in 1986. Now, this pair has brought scientists and photographers to the chilly Morro Bay waters, straining pairs of eyes hoping to glimpse and study the otters as they rest and float near the kelp forests.

“They’re pretty rare situations,” Staedler said. “This is the fourth one that I know of.”

This is nature at its most adorable and cruel. Eventually, one of the pups will have to be abandoned; caring for twins is too tiring and metabolically taxing for a mother sea otter. Scientists aren’t sure how long both pups can stay with their mom, but their estimates are on the order of days — not weeks. Once a pup has been let go it might survive for another 24 hours or so — unless it’s rescued and raised in captivity.

In Morro Bay, scientists at the U.S. Geological Survey and California Department of Fish and Game noticed the pair of pups early on Monday and guessed they’d been born over the weekend. By Monday afternoon, teams were monitoring the trio. Photographer and State Park docent Mike Baird set out to capture photos of the otter family from the shore near Target Rock, and produced the images we’ve featured above.

On Tuesday, Staedler arrived in Morro Bay to study the family’s behavior, ready to retrieve an abandoned pup and bring it back to the Aquarium for fostering. “[The mother] did a really good job of keeping on top of everything, and watching the two. She was very attentive to both of them,” Staedler said. “If one drifted away, she would go back and pick it up and get it and put it on top of her.”

And then the fog rolled in and the otters disappeared.

By Wednesday, it appeared there was only one pup left. Heavy fog and long distances have made confirmation difficult, but no one has seen a mom with two pups. Instead, an otter who appears similar to the twins’ mother has been sighted with just one little pup.

Now, teams in the area are searching for any sign of a drifting or stranded baby otter. If they find it alive, they’ll bring it to the Aquarium to be fostered. It wouldn’t be the first time: In 1986, researchers studying the first documented otter twins watched as one of them drifted away, then brought the abandoned pup to the Aquarium, where she was cared for and raised as a captive otter.

The outcome for this pair is still uncertain, but we’ll update this story when we know.

Update, 10:45 a.m. Pacific: Scientists are out looking for the otter mom, but she is hard to identify.

“She is decidedly lacking in distinguishing characteristics, such as nose scarring (incurred during mating—hers is perfectly black) or unusual grizzle (the lighter fur color on the head and body of some otters–hers is fairly average),” writes Gena Bentall, a marine biologist with the U.S. Geological Survey. “Her one distinguishing feature was the presence of two pups and that is extremely unlikely to have persisted long beyond our last sighting.”

7:15 p.m.: Mike Baird reports that an observer saw the otter with two pups on Wednesday; no sightings of the twins on Friday yet.

June 29, 11:15 a.m.: Still no word on the otters. But we do have some important information to share about why biologists can’t simply go out and retrieve one of the pups.

“We have no legal authority under our permits for working with sea otters to intervene and anticipate that a situation like that won’t work out. “We can only take a pup into our program if it is clearly separated from the mother, in distress or washing up on shore,” writes Ken Peterson, the Aquarium’s communications director. Teams in the field are working within the rules established by wildlife officials charged with bringing sea otters back from their current endangered status.

And, Peterson notes, “In the highly unlikely event that we could get permission from the U.S. Fish and Wildlife Service to intervene and take one of the pups — in doing so we could so agitate the mother that she would abandon both of them.”

Under no circumstances should you attempt to approach a sea otter; you must stay at least 150 feet from them (more information is here). Sea otters are protected by the Marine Mammal Protection Act, which makes it illegal to harass, capture, hunt, or kill any marine mammal (with some exceptions, which include things like permits granted to scientists).

July 2, 2:15 p.m.:

Michael Harris, a sea otter biologist with the California Department of Fish and Wildlife, reports the following: “I just returned from checking on this group of otters,” he writes. “The female I believe to be the mom that had the twins is still in the area and she continues to care for a single pup. Both mom and pup appear to be doing well.”